The imaging core has two components that provide major support to the center investigators. The Microscopy Component provides the following: 1) high resolution 3- dimensional imaging of parameter-sensitive fluorophores in living cells and tissues by laser scanning confocal microscopy to monitor ions, electrical potentials, oxygen radical generation, pyradine nucleotide reduction, mitochondrial and plasmalemmal membrane permeability, and cell viability (apoptosis and necrosis); 2) intravitral microscopy using a "real time" confocal microscope to monitor microcirculation, leukocyte margination and gene expression in specific cell populations of the livers of anaesthetized rats; 3) high resolution confocal imaging of tissue sections for immunocytochemistry, fluorescence in situ hybridization and green fluorescent protein; 4) a digital darkroom facility for digitizing images, analyzing and labeling these images, and printing the processed images as photographic quality prints and slides for use in publications, reports and oral presentation; and 5) a fluorescent plate reader for measuring cell viability and intracellular ions in cultured cells grown on multi-well plates. The Pathology Component provides consultation, training and services in basic morphological and immunohistochemical techniques for preparation of frozen and paraffin sections of histology, immunocytochemistry, and in situ hybridization. The Pathology Component routinely handles H&E, PAS, eosin, and trichrome staining of brain, liver and other tissue and provides immunocytochemical staining for glial fibrillary protein (GFAP), myelin basic protein (MBP), lectin binding and other cellular components of interest.